Department of Mechanical Engineering, Kyung Hee University, 17104 Yongin, Republic of Korea.
Nanoscale. 2018 Sep 20;10(36):17125-17130. doi: 10.1039/c8nr04873h.
The combined characteristics of non-wettabililty and strong plasmonic resonances make superhydrophobic plasmonic nanostructures an appealing tool for ultrasensitive detection in surface-enhanced Raman scattering (SERS). However, inducing superhydrophobic surfaces on originally hydrophilic metals (e.g., gold, silver) while achieving high plasmonic enhancement requires sophisticated surface engineering and often involves complex fabrication processes. In this article, we design and fabricate cost effective and scalable plasmonic nanostructures with both superhydrophobicity (a water contact angle >160°) and high SERS signal (enhancement factor ≈106). Silver-coated aluminum hydroxide nanotemplates are obtained from a simple wet process, followed by thermal evaporation of silver nanoparticles. We find that the largest SERS enhancement is obtained when the contact angle is maximum. This confirms that the control of surface wettability is an effective way to improve detection sensitivity in SERS measurements. The nanotemplates developed in this study could be applied further in various applications, including microfluidic biomolecular optical sensors, photocatalysts, and optoelectronic devices.
超疏水性和强等离子体共振的综合特性使超疏水等离子体纳米结构成为表面增强拉曼散射（SERS）中超灵敏检测的一种有吸引力的工具。然而，在原本亲水的金属（例如金、银）上诱导超疏水性，同时实现高等离子体增强，需要复杂的表面工程，并且通常涉及复杂的制造工艺。在本文中，我们设计并制造了具有超疏水性（水接触角>160°）和高 SERS 信号（增强因子≈106）的具有成本效益和可扩展性的等离子体纳米结构。银涂覆的氢氧化铝纳米管模板是通过简单的湿法工艺获得的，然后通过热蒸发银纳米粒子。我们发现，当接触角最大时，获得了最大的 SERS 增强。这证实了控制表面润湿性是提高 SERS 测量检测灵敏度的有效方法。本研究中开发的纳米模板可进一步应用于各种应用，包括微流控生物分子光学传感器、光催化剂和光电设备。
